Outgoing Energy Secretary Steven Chu will not attend the State of the Union, the White House announced Friday.

Because the president, vice president, lawmakers, Cabinet secretaries, Supreme Court justices and members of the military’s Joint Chiefs of Staff are all sitting together in a confined space in the Capitol, one Cabinet member is chosen to skip the speech every year.

The tradition dates back at least to the 1960s and the White House first publicly released the names of designated absentees during the Nixon administration, according to the Senate Historical Office.